WATER

Drought defence

It is no secret any more, according to experts, South Africa is officially experiencing a water crisis. When it comes to fixing the disaster at hand, current estimations average around R680 billion, with a strong message that Government could have acted sooner.

With water restrictions already in place in provinces such as Gauteng, Water and Sanitation Minister, Nomvula Mokonyane, recently announced that the drought currently plaguing the country will last for at least another three years. Efforts are however under way to bring together top industry stakeholders in the sector to deal with the matter at hand.

The annual African Utility Week remains a leading platform for knowledge sharing and collaboration in the vital industries of water and energy. After a successful round in 2015, the 2016 line-up looks equally impressive with delegates from across the continent and the world who will be attending.

Opportunity was afforded an exclusive with Steve Gilham who will be speaking at African Utility Week in May 2016 in Cape Town on the topic of ‘Assessing large scale seawater desalination as a regional water supply option’. Gilham, a registered professional engineer, has spent his entire working career in the water sector in South Africa. Initially employed by the Department of Water Affairs, he is currently General Manager: Engineering & Scientific Services at Umgeni Water responsible for the planning, design and implementation of the organisation’s infrastructure programme, as well as its water resource management, treatment processes, and water quality monitoring and analysis.

As Gilham points out, South Africa is a water-scarce country defined by a low level of annual rainfall received compared to the global average—coupled with high variability of this rainfall and a high level of evaporation as a result of the hot climate. “The country is classified as being water stressed where collectively the available resources are insufficient to meet the needs. Water availability varies spatially across the country, so some areas have sufficient resources at present whilst other areas do not.

“The current lack of surface water availability and limited further development potential will strain the country’s ability to fully support its growing economical requirements. The agricultural sector is the largest consumer (approximately 60%) of water in South Africa, followed by the municipal/domestic sector at around 27%. Other large consumers of water are the industrial, power generation and mining sectors,” he says.

Gilham says that for the economy to grow and prosper, it requires a productive and healthy population which is constantly improving. He says the lack of access to clean water has a direct impact on those in the population who are affected, which in turn impacts the economy. With unclean water and sources that are often far from communities, many able bodied community members, especially women, are forced to spend hours each day finding and transporting water. Gilham says this water often contains water-borne diseases that cause health complications, further exacerbated by poor sanitation conditions and the inability to sanitise with water. Hence, it remains difficult for these communities to break out of the cycle of poverty according to him.

He also highlights that as the availability of clean water in the natural water courses is diminishing a result of interference and exploitation by humans–the need to treat this water to a potable standard and then make it readily available becomes more critical. Gilham does however point out that there are many uses for untreated water, particularly in the agricultural sector when looking at irrigation and stock watering.

“The water quality requirement for industrial purposes depends on the type of industrial process that it is used for and can range from untreated to a treatment level higher than that required for human consumption. In most instances, industrial water can be supplied at a quality slightly less than that required for human consumption. However, it is more practical to supply industry with the same potable water that is supplied to domestic users,” he says.

Looking at water pollution, Gilham says it may emanate from a large number of sources including agricultural, industrial, mining and municipal wastewater, but points out that the situation various by region depending on the predominant sector in that region or catchment. According to him, the issues relating to resolving acid mine drainage are well known and are being tackled by both the private and public sectors.

The Department of Water & Sanitation plays a regulatory and oversight role in monitoring, limiting and preventing pollution instances, Gilham says. According to him, catchment management agencies are in the process of being established throughout the country with one of their roles being to safeguard the water quality within the country’s catchments. Municipalities also have a role to play to ensure that industrial polluters are addressed and that their sewer systems and wastewater treatment plants are operated and maintained at an acceptable standard.

Gilham says water catchment areas remain the source of the water supply chain. “The amount of runoff that is produced and the quality of this water are governed by how well a catchment is being managed. Here again, the quality of management varies tremendously across the country from excellent to very poor. People often fail to recognise the link between healthy catchments and water supply and thus allow land use practices to occur which are counterproductive.

“The term ecological infrastructure has been recently adopted to refer to naturally functioning ecosystems that deliver valuable services such as fresh water to people. There are an increasing number of initiatives being launched to promote the safeguarding of our ecological infrastructure, particularly in key water supply catchments such as the uMngeni. A proposal has been submitted to include Ecological Infrastructure for Water Security as SIP 19,” he says.

When asked about some of the most sought after skills in water treatment and management at the moment, Gilham says operators of water treatment plants are required to obtain certain registrations depending upon the size plant that they are operating to demonstrate their competence. He says there are still many treatment plants in the country that do not have the correctly qualified operators running their plants. “Process technicians and engineers also play an important role in ensuring the efficient operation of a water treatment plant. With the extent of water losses being experience throughout the country, there is a dire need to train plumbers at a reticulation/household level of expertise to assist in addressing this problem.

“Water management at a strategic and regional scale requires a comprehensive and in-depth knowledge of how the water sector functions throughout the entire water cycle, whilst understanding its challenges and constraints. This type of knowledge cannot be gained through academic study alone and requires people that have been exposed to the sector for a number of years. Engineers with experience in regional water resource and supply infrastructure planning at a strategic and detailed level appear to be in short supply,” he says.

Discussing some of the latest technologies being used in water treatment at the moment, Gilham says there has been a move towards utilising membrane technology as a filter media in more instances. “South Africa lags behind the developed world in this regard. As the costs relating to this technology reduce, confidence and knowledge of the application increases, and the quality of the water requiring treatment deteriorates, there will be a greater momentum shift in this direction.

“Conventional treatment methodologies are still effective. There is continual research and innovation in terms of finding ways to improve the efficiencies, reduce production costs and reduce the footprint size of these processes. The new technologies range from silt removal mechanisms throughout the process to disinfection,” he says.

On a topic Gilham is quite well acquainted with, desalination, he says seawater desalination provides an alternate source of potable water to the conventional surface and groundwater options, with the major advantage that it is drought proof. He does however point out that there are a number of constraints to the widespread application of seawater desalination in South Africa, including high energy requirements, and the fact that it only has application for consumers situated close to the coast.

Gilham says at this point in time the cost to produce and supply desalinated seawater is far higher than the cost of supplying treated water from a conventional source. He however says as technologies and efficiencies relating to desalination improve and thereby reduce the costs, whilst the cost of water from conventional sources continues to grow, there will be a point where desalination will become a competitive option to supply cities and towns situated along the coast. According to him, in some areas of the country, this point is not far off.

“When the implementation of seawater desalination plants becomes an economically viable reality, private sector expertise will need to be brought in in one form or another. There are various institutional models which can be applied to the design, build, financing, ownership, operation, maintenance and hand-over components, structured in a variety of combinations. There are numerous examples of each throughout the world. Selecting the appropriate model will be based on each individual projects characteristics and who the project sponsors are,” he concludes.